Device for testing typewriter ribbons



Dec. 10, 1929.

m M m CZvrl Filed Feb. 4, 1928 C J KANNEWISHER DEVICE FOR TESTING TYPEWRITER RIBBONS Patented Dec. 10, 1929 man-w.

CARL J. KANNEWISH EP, OF ROCHESTER, N YORK :onvron For, rne'rrne application filed February The present invention relates to typewriting machines and more particularly to attachments therefor and it has for its object to provide an ordinary typewriter or similar TYPEVJIRITER ItIBlBONS machine with means whereby an inking ribbon can be temporarily attached in such a way as to give an opportunity for testing 1ts quality and durability. The general purpose is to subject a relatively small trial area of the ribbon in a shortspace of time to a great number of type impacts or impressions or until the repetitions have demonstrated the wear with which, by calculation, the ribbon would become worthless in actual use. The improvements are directed in part toward the provision of a detachable ribbon holding means for this purpose which will be simple and inexpensive in construction and convenient and efficient in use.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Figure 1 is a front view partly broken away of the platen, type bar guide and associated parts of a typewriter showing an attachment constructed in accordance with and illustrating one embodiment of my invention F fgure 2 is an enlarged section on the line 22 of Figure 1;

Figure 3 is atop plan view of the attachment in one form;

Figure 4 is a perspective view thereof Figure 5 is an enlarged section on the line 5-5 of Figure 3;

Figure 6 is a perspective View of a modified form of attachment; and

Figure 7 is a fragmentary elevation of a portion of Figure 1 showing the modified attachment of Figure 6 in position.

Similar reference numerals throughout the several views indicate the sameparts,

A familiar standard type of typewrlter construction in connection with which I have, in the present instance, illustrated and 5 will describe my invention embodies a cy- 195% Serial N0. 251,806.

lindrical platen 1 turned by knobs 2 at its ends to feed a sheet or strip of paper (not shown) there around, the paper passing beneath or in rear of a fixed type guide shown generally at 8. Types f on pivoted type bars 5 sn'ike through the type guides against the platen and the paper, and an inking ribbon being fed continuously between the type and platen, an inked impression is made upon the paper. The printing point is indicated at A in Figure 1 which is the position of the type in that figure. The inking ribbon being a moving ribbon, as aforesaid, no two successive blowsor impacts of the type occur at the same point on the ribbon surface until the whole ribbon has passed through the machine but as the ribbon is reversed and fed back and forth in a Well known manner, every point thereof is ultimately subjected to a repetition of its inking function and the number of such. repetitions that it will stand determines its life and depends upon various character istics of quality. 1 v

To quickly test such a ribbon for durability, my invention contemplates stretching a short selected length thereof or, for instance, an end of a complete ribbon, across the printing point in a fixed position relatively to the platen so that, without feeding it, successive blows of a type are repeatedly re ceived upon very few, say five or six, points of the surface and, as the paper is fed laterally past the printing point and the platen carriage shifted within restricted limits, a record of the ultimate performance of which the ribbon is capable, is obtained. The record test sheet will show a number of short lines, the first of which will be clear and distinct while the ribbon is fresh and will gradually fade, progressively, until a point is reached where the inked impression is too faint to be satisfactory or useful. This marks the point at which the ribbon, in use, would have to be discarded and the number of lines on the test sheet to this point is an index of the quality' and life of the ribbon as, through calculation, this may be used to determine how long an. enitre working length of such a ribbon will last and how many impressions it will satisfactorily record under normal In the practice of my invention and to the,

ends above described, I providetwodetach:

- able clips which,' on the occasion of atest,

may be slipped into tempor ary engagement with these fingers and support a section of ribbon'stretched in a fixedzposition across the printing point A. A preferred form of this clip. is shown in'position in; Fignresl and. 2

and indetail in. Figures 3-, at and 5. It comprises. a substantially. flat plate havingenlargedi end portions 7 and, 8. and aa relatively narrow. central waist portion 9. from which is struck up a tongue 10 pro ectmg toward theenlarged end: 5. Along the edge of this 611d]301t1011,5 are arranged 1n a row a plurality of; impaling pins 11 constituted in the present instance striking up spurs from the metal sheet, At separated points along the length of the plate are two rounded bosses ortprotuberances .12 that may be made by bumping out the material as clearly shown v in Figure 5',

In use, the plateis, clipped over, the pressure finger 6 with. he w i t por ion 9 disposed beneath and thespring tongue 10 on f top at; a point just. abOVQ'the center of the platen roll- 1. In some typewriter construc- 1 tions thetongne thus lies betweena roller 13 the, nger a d a nger pi c ange 14 struck up from the edge thereof, The ends ofasection of ribbon indicated at Bare impaledcunon h e p t-ir e of p o that the ribbon is drawn taut across the print- {ing poin a The fingersfi-are usually slid- .ably mountedtowardand from each other. along the length ofthe platen so that this 7 operationis thereby additionally facilitated.

The. specimen ribbon is then immediately ready for the test in the manner first decribe a While the platenand ribbon move together longitudinallyithey move relatively as the platen, is turned. and the pa'per'is fed from line to line. -The, clip plate vbeing heldby the finge sa nst' hep per 1 p t s hu suhjectedlto some frictional contact, but this 1s much reduced'by therounded bosses 12 a ai'nst which the contac-t'occurs'and there is small likelihood of'the clip being displaced.

Additionall'y'y'the outer edge of the finger 6,

because eras curvature, engages the. shoulders formed at by the enlargedend por- ""tion Swhich engagement is maintained to some extent by the ribbon itself.andthis also tends to prevent displacement Iof. the clip,

plate. The bosses12 being arrangedyone on each sideofthe fingern6, equalizes thefrictional pull upon the attachment due to the turning of the platen and feeding of the paper and act to further prevent the clip from being cocked or turned away. They also, in riding on the platen, space the clip away from the surface of the latter to make room forthe paper when the paper strip is narrow and lies on the platen intermediate the clips.

In the preferred form of my invention as described, the attachment is symmetrical in form and no rights and lefts are required for the reason that either the upper two or the lower two of the impaling pins shown at It may be used according to whether the clip is applied to the finger 6 at the left or the one at the right, will be understood frpm an inspection of Figure 1.

The modified formof the invention shown inFigures 6 and 7- must be made in rights and lefts, althonghit is a very simple construction. In that construction the body of the plate 9 is provided with an extended serrated flange 11 at one edge, the opposite edge being doubled back to form a spring tongue 10. This engages under the linger 6 as shownin Figure 7 andthc body of the plate on the top of the finger. The ribbon is attachedin the same manner.

I claim as my invention 1-. The combination with the platen of a typewriter having types coperating therewith ata printing point; and paper pressure fingers associated with the platen at each side of the printing. point, of detachable sheet metal, clips having spring tongues, clipped over the fingers, and provided with impaling points uponwhich an inking ribbon may be fixedly secured to stretch between the platen and the types across the printing point,

2. The combination with the platen of a typewriter having typescooperating therewith at a printing point and paper pressure fingers associated with the platen at each side of: the printing point, ofdetacha hle sheet metal; clips having spring tongues clipped over the fingersand provided with impaling points upon which an inking ribbon may be fixedly securedto stretch between the platen and the types across, the printing point, said clips beingfurther. provided with rounded contact points projectingfroin their under. sides to ride against thesur-face of the paper and platenwhen moved-wider it to reduce the frictional contact 3. The combination with the cylindrical platen of a typewriter having types coperatingtherewith at, a printingpoint and curved paper pressure fingers associated with 1 the platen at eachside of'the printingpoint, of detachable sheet metal clips having spring tongues clipped on the,fingersandprovided with ,iinpaling points upon which an inking ribbon may befixedly securedito stretch between the platen and the types aeross; the printing point, said dips being provided with shoulders engaging the edges of the fingers to assist in maintaining their positions on the fingers.

4. As an article of manufacture, a clip for P the purposes set for comprising a metal plate having impaling points struck up therefrom, and a spring attaching tongue, the under side of the plate being provided with rounded frictionless bosses.

5. As an article of manufacture, a clip for the purposes set forth comprising a symmetrical metal plate having enlarged ends, one of Which provides lateral inner shoulders, and a central Waist portion having a spring tongue struck up therefrom, the other enlarged end being provided with a plurality of impaling points for an inking ribbon, the end portions being embossed on their under sides to produce rounded anti-frictional projections.

CARL J. KANNEVVISHER. 

